With the rapid development of smart terminals, the photographing function of the smart terminals becomes more and more frequently used, especially for photographing people. Shopping malls, attractions, and places of interest can be commonly seen with people taking group photos or selfies. In the industry currently, cameras in the terminals usually support face focus function, a technology in which focusing is triggered based on detection of the facial region. That is, focusing and photographing are realized with the face as the best clear point of focus.
When photographing the face, an automatic focus (AF) mode is usually triggered to complete the photographing after a facial region of interest (ROI) obtained is stable. However, movements of the object during the photographing may blur the photograph obtained.